1. Field of the Invention
The present invention relates to a data communication apparatus and, more particularly, to a data communication apparatus for transmitting "receive" data to another data communication apparatus designated beforehand.
2. Related Background Art
A facsimile apparatus for performing multi-address transmission (so-called relay multi-address) of receive image data to a designated destination (i.e, a called station) is known as a conventional apparatus of this type.
If there are many destinations to which an original is to be sent, an original image is temporarily stored in a memory and is automatically transmitted to the destinations in a given order. This facsimile transmission is called multi-address transmission. In addition, an operation for transmitting image data received in a memory to a plurality of stations is Galled relay multi-address transmission.
A facsimile apparatus capable of performing relay multi-address communication signals this function by using a signal (NSF signal in G3 protocol) representing a nonstandard apparatus to an image transmitting end.
When an operation for designating relay multi-address communication is required for a user at a transmitter, it detects in accordance with the above signal that a receiver has a relay multi-address communication function. Upon detection of this function, the transmitter designates relay multi-address communication by using a nonstandard apparatus setting signal (i.e., an NSS signal) and then transmits the image subjected to relay multi-address communication. Therefore, the receiver can sequentially transmit the image data to all called stations in accordance with a relay multi-address communication scheme.
Since the presence/absence of the relay multi-address communication function is detected and the relay multi-address communication is designated in a conventional system in accordance with the nonstandard function signals such as NSF, NSS, and NSC signals, relay multi-address communication can be performed between only facsimile apparatuses manufactured by the same manufacturer and cannot be performed between facsimile apparatuses manufactured by different manufacturers. In addition, relay multi-address communication can be designated from only the transmitter side. It is impossible to perform processing such as automatic transfer of image data at the receiver side.
Relay multi-address communication is disclosed in U.S. Pat. No. 4,785,355, but this proposal cannot solve the conventional problems described above.